[Unity] AnimationClip renaming issues and editing conflicts in Skeleton Mecanim

firefly3213

Hi Spine Team,

I am writing to seek technical support regarding the Spine-Unity runtime, specifically when using the Skeleton Mecanim component.

In my Unity project, after converting Spine animations into Mecanim clips, I encountered the following issues:

Renaming breaks functionality: If I duplicate the automatically generated .anim file and change its name, the clip no longer plays correctly in the Unity Animator. It appears that the clip must retain its original name to stay linked with the Spine data.

Editing conflict in Animation Window: My goal is to have two versions of the same animation with different Animation Events on their timelines. However, because I cannot rename them, Unity's Animation window dropdown only shows one entry due to the name duplicate, making it impossible to switch between and edit them individually.

My Question: What is the recommended workflow in Unity to correctly clone and rename these generated .anim files so that they remain functional while allowing for individual identification and editing in the Animation window?

Note: Please note that English is not my native language, and I have used AI to assist in drafting this inquiry to ensure clarity. I sincerely apologize if there are any technical inaccuracies or if any part of my description is unclear.

Thank you for your time and for the amazing work you do with Spine!

Best regards,

Firefly

firefly3213

Spinebot Thank you so much for the detailed explanation! It really helped me understand that these .anim clips are "virtual" triggers rather than traditional Unity animation data.

Regarding your suggestion to add events within the Spine editor, I have a specific constraint that prevents me from doing so:

The Spine assets I am using were downloaded from an online source. I only have the exported textures, .atlas, and .json (or .skel) files. Since I do not have the original .spine project files, I am unable to restore the animations in the Spine editor to add or modify events.

This is precisely why I am trying to manually add Animation Events within Unity. However, as we discussed, the inability to rename these clips and the resulting name conflicts make it impossible to create multiple versions of the same animation with different sets of events.

I apologize again if any of my technical descriptions are inaccurate, as I am using AI to assist with my English communication.

Thank you again for your patience and for helping me find a solution!

Best regards,

Firefly

Harald

@firefly3213 I've deleted Spinebots reply as some of the points were perhaps correct in the past, but many are no longer are true.

How a SkeletonMecanim AnimationClip works:
It is just a dummy placeholder clip which serves two purposes:

It holds a name property m_Name which determines the Spine animation to be played (as Spinebot correctly said).
It holds events, typically generated from Spine events, which are played back via the normal Mecanim event logic (see documentation here).

Regarding the name:
Note that the m_Name property can be different from the actual asset name. Unity issues a warning "The main object name <name> should match the asset filename. Please fix to avoid errors", but it still works regardless. You can duplicate the AnimationClip (e.g. gun-grab) then rename the asset (to gun-grab-alt) and in a text editor open the new file (gun-grab-alt.anim) and in it change the m_Name back to gun-grab to play the existing animation gun-grab. The drawback is that some fields display the m_Name instead of the asset name (so gun-grab everywhere), making it harder to distinguish between multiple variants like gun-grab and gun-grab-alt.

Regarding custom events:
While it's much more recommended to add events in Spine, you can manually add events inside Unity via the Animation window, these events are preserved upon re-import in any reasonably recent spine-unity version. If you move Spine events around or delete them, this will be detected and automatically adjusted in newer spine-unity version, and your custom added events left unaffected [1].

[1] It's encoded via a special string/int/float parameter value which identifies whether an event is an event coming from Spine or a custom manually added Unity event.

Regarding renaming animations: This is not as well supported, but you can open the existing skeletonname_Controller.controller asset file in your text editor and in it replace any occurrance of your old animation name (gun-grab) with your new animation name (e.g. gun-draw). The order is important however, otherwise you

firefly3213

Harald Hi [Harald],

Thank you so much for your detailed and "deep-dive" explanation!

The "text editor" solution for modifying the m_Name worked perfectly to resolve the playback issues. I also truly appreciate you stepping in to correct the outdated information provided by the bot—knowing the current logic of the Spine-Unity runtime is incredibly helpful for my workflow.

Regarding the UI visibility issue in the Animation window, I’ve found a solid workaround: editing the Events list directly via the Inspector panel of the .anim file. This allows me to bypass the dropdown list and avoid the conflict caused by duplicate internal names.

Thank you again for your professional support and patience. You guys are doing an amazing job with the Spine-Unity runtime!

Best regards,

Firefly

Harald

@firefly3213 Thanks very much for your kind words, glad it helped and you've found a suitable workflow!

I assume you are already using it, but to be sure:
Please make sure to enable Scene Preview at the SkeletonMecanim component to preview the state of the Animation window: the currently selected clip with the current playhead position. This should make is far easier to place your Unity events precisely.